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ARTICLE Dietary changes and food intake in the first year after breast cancer treatment1 Appl. Physiol. Nutr. Metab. Downloaded from www.nrcresearchpress.com by CONCORDIA UNIV on 05/30/14 For personal use only.
Vivienne Vance, Sharon Campbell, Linda McCargar, Marina Mourtzakis, and Rhona Hanning
Abstract: Understanding dietary habits of women after breast cancer is a critical first step in developing nutrition guidelines that will support weight management and optimal health in survivorship; however, limited data are available. The objective of this study was to describe changes in diet among breast cancer survivors in the first year after treatment, and to evaluate these changes in the context of current dietary intake. Changes in diet were assessed in 28 early stage breast cancer survivors, using a self-reported survey in which women identified changes in food intake since their diagnosis. Current dietary intake was estimated from 3-day food records and described relative to current recommendations. The majority of women reported changes in diet after diagnosis, most common being an increase in vegetables/fruit and fish, lower intake of red meat, and reduced alcohol. Many women reported that these changes were initiated during active treatment. Dietary changes were largely consistent with current recommendations for cancer prevention; however, some women were still above the guidelines for total and saturated fat, and many were below recommendations for vegetables/fruit, milk/alternatives, calcium, and vitamin D. Evidence that some women are willing and able to initiate positive changes in diet early in the treatment trajectory suggests that early intervention may be effective in promoting dietary habits that will assist with weight management and overall health. Data on current dietary intake highlights several possible targets for dietary intervention in this population. Key words: diet, dietary change, breast cancer, body weight, survivorship. Résumé : Comprendre les habitudes alimentaires des femmes ayant eu un cancer du sein est la première étape critique pour élaborer des directives en matière de nutrition qui aideront au contrôle du poids et au maintien d’une santé optimale chez les survivantes; toutefois, il y a peu d’études sur ce sujet. Cette étude se propose de décrire les modifications du régime alimentaire chez les survivantes du cancer du sein durant la première année suivant le traitement et d’évaluer ces modifications dans le contexte du régime alimentaire actuel. On évalue les modifications au régime alimentaire depuis le diagnostic de 28 survivantes du cancer du sein au stade précoce au moyen d’une enquête d’autoévaluation demandant d’indiquer les changements effectués a` l’apport alimentaire. On évalue l’apport alimentaire d’après le rappel de 3 jours et on le compare aux recommandations actuelles. La majorité des femmes rapportent des modifications dans leur régime alimentaire a` la suite du diagnostic, les plus fréquentes étant plus de fruits/légumes et de poisson, moins de viande rouge et d’alcool. Plusieurs femmes rapportent que ces modifications ont été amorcées durant le traitement. Ces modifications des habitudes alimentaires étaient très conformes aux recommandations actuelles pour la prévention du cancer, mais quelques femmes consommaient plus de gras, total et saturé, et moins de fruits/légumes, lait–substituts, calcium et vitamine D que ne le stipulent les recommandations. Le fait que des femmes veulent et arrivent a` modifier positivement leur régime alimentaire au début de la trajectoire du traitement suggère qu’une intervention précoce semble efficace pour la promotion de bonnes habitudes alimentaires utiles au contrôle du poids et a` la santé globale. Les données au sujet de l’apport alimentaire actuel mettent en évidence plusieurs cibles a` viser pour des interventions en matière d’alimentation auprès de cette population. [Traduit par la Rédaction] Mots-clés : régime alimentaire, modification alimentaire, cancer du sein, poids corporel, survie.
Introduction The population of breast cancer survivors in Canada and the United States is growing substantially, with more than 250 000 new cases expected each year and significant improvements in survival rates since the mid-1980s (Canadian Cancer Society’s Steering Committee on Cancer Statistics 2011; National Cancer Institute 2011a). Many of these women gain weight, both during and after treatment (Vance et al. 2011). Furthermore, with or without weight gain, gains in body fat and loss of lean tissue are prevalent in
this population (Vance et al. 2011; Rock and Demark-Wahnefried 2002; Visovsky 2006). These unfavourable changes in body composition are distressing for many women (Knobf 1986; Halbert et al. 2008) and may lead to metabolic disturbance (Robinson and Graham 2004), increased risk of obesity-related disorders (Brown et al. 1993; Wingo et al. 1998), and poorer prognosis (Nichols et al. 2009; Chen et al. 2010; Thivat et al. 2010). As prevalence increases, the need for dietary counseling and nutrition intervention to support healthy eating, weight management, and optimal health after diagnosis is expected to grow.
Received 26 August 2013. Accepted 6 November 2013. V. Vance,* S. Campbell, and R. Hanning. School of Public Health and Health Systems, University of Waterloo, Waterloo, ON N2L 3G1, Canada. L. McCargar. Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB T6G 2E1, Canada. M. Mourtzakis.† Department of Kinesiology, University of Waterloo, Waterloo, ON N2L 3G1, Canada. Corresponding author: Vivienne Vance (e-mail: [email protected]). *Present address: Health Sciences Program, Wilfrid Laurier University, 75 University Ave, Waterloo, ON N2L 3C5, Canada. †All editorial decisions for this paper were made by David Ma and Terry Graham. 1This paper is a part of a Special Issue entitled The role of diet, body composition, and physical activity on cancer prevention, treatment, and survivorship. Appl. Physiol. Nutr. Metab. 39: 707–714 (2014) dx.doi.org/10.1139/apnm-2013-0400
Published at www.nrcresearchpress.com/apnm on 20 November 2013.
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The ideal diet for breast cancer survivors is uncertain at this time; however, current evidence suggests that a diet aimed at primary prevention may also improve long-term disease-free status (World Cancer Research Fund/American Institute for Cancer Research 2007) and overall survival (Kroenke et al. 2005; Kwan et al. 2009). Thus, a predominantly plant-based diet that promotes a healthy body weight, is low in fat, rich in whole grains, and comprises a variety of fruits and vegetables is currently recommended for women who have undergone treatment for breast cancer (Hauner et al. 2011; BC Cancer Agency 2012). In addition, adequate calcium and vitamin D intake is necessary to support bone health, particularly since many breast cancer survivors are menopausal at diagnosis (Canadian Cancer Society’s Steering Committee on Cancer Statistics 2012) and many others will become menopausal as a result of treatment (Canadian Breast Cancer Foundation 2012a). With these guidelines in mind, understanding dietary habits of women after diagnosis is an important first step in developing intervention strategies. At this time there are very limited data concerning dietary changes made by women after a breast cancer diagnosis, particularly early in the treatment trajectory when these changes are initiated, and how nutrient intakes in this population compare with current recommendations. The objective of this study was to describe selfreported changes in diet among breast cancer survivors (National Cancer Institute 2011b), who were within the first year of completing chemotherapy treatment, and to evaluate these changes in the context of current dietary intake. These findings may help to identify factors associated with energy imbalance after primary treatment and will provide a preliminary basis on which to develop nutrition guidelines to inform dietetic counseling and intervention.
Materials and methods Participant recruitment Data for this study were collected as part of a more extensive study in which breast cancer survivors participated in qualitative interviews to explore individual experiences of food intake and weight change during chemotherapy. Participants were recruited from southwestern Ontario, Canada. Eligibility requirements included female breast cancer survivors aged >18 years, clinical stage I–IIIA, within 12 months of completing chemotherapy, and able to communicate freely in English (oral and written). The study received clearance from the Office of Research Ethics, University of Waterloo. Participants were recruited through professional organizations/events (e.g., Canadian Breast Cancer Foundation Run for the Cure), community support groups, and local businesses. Advertisements were also posted in several newspapers, the Well-Fit Centre at the University of Waterloo (group exercise program for cancer patients), and the Grand River Regional Cancer Centre, Kitchener, Ontario. Interested participants contacted the researcher via telephone or email, were screened for eligibility, and provided with a detailed information letter. Eligible participants were contacted again within 1 week to review study details and respond to questions. Interviews were scheduled within 2 weeks in the participant’s home or at the University of Waterloo, based on participant preference. Demographic, clinical and treatment information were collected via detailed questionnaire, which was completed with the researcher. Written consent was provided by all participants. Dietary changes after diagnosis Changes in diet after diagnosis were assessed using an initial “filter” question that asked “since your diagnosis have you made any changes to the kinds of foods you eat?” Women who indicated that they had made changes to their diet were asked to elaborate about specific changes in food groups/dietary components. Nine
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diet categories, adapted from previous research with breast cancer survivors (Maunsell et al. 2002) and grounded in current dietary recommendations for healthy eating (Health Canada 2007), were evaluated including vegetables and fruit, legumes, meat, fish, dairy products, breads/cereals, desserts, alcohol, and supplements. Participants were asked to indicate whether they had “introduced”, “increased”, “decreased”, or “eliminated” these items from their diet since their diagnosis. In addition, 4 items were further explored to determine if there had been a “change in type”, including meat, dairy products, breads/cereals, and supplements. Based on the work of Maunsell et al. (2002), changes were categorized as positive if intake of vegetables and fruit, legumes, and fish were reported as increased (or introduced) and if intake of meat, desserts, and alcohol were reported as decreased (or eliminated). Changes in dairy products and breads/cereals were considered positive if women reported consuming products with a lower fat content or higher fibre content, respectively. Added to this study was 1 additional positive change: a “change in type” for meat intake (lower fat content). Changes in dietary supplement use were of interest; however, in the absence of clear evidence (Greenlee et al. 2009) these changes were not classified as positive or negative. Three-day food records Current dietary intake was assessed using a 3-day food record. Two weekdays and 1 weekend day were included, to control for possible day-of-the-week effects (Trabulsi and Schoeller 2001). Detailed verbal and written instructions for recording daily food intake and a “sample day” were provided. Participants were encouraged to provide as much detail as possible and to use household measures (teaspoons, measuring cups, scales) and food labels to estimate serving sizes. During the recording period, participants were contacted by telephone or email to see if they had any questions or concerns. Completed records were reviewed with participants for clarification and completeness. Data analysis Descriptive statistics were used to characterize the sample group and to identify the nature and extent of self-reported changes in diet since diagnosis. Specific components of current dietary intake were selected for analysis (energy, macronutrients, fibre, vegetables/fruits, milk/alternatives, calcium, vitamin D), based on current guidelines to support weight management and optimal health after diagnosis. Nutrient analysis was conducted using The Food Processor SQL version 10.5.2 (Esha Research, Salem, Ore., USA), including the current Canadian Nutrient File Database (Health Canada 2010). Servings of vegetables/fruit (total, dark green/orange vegetables) and milk/alternatives were hand calculated, based on servings sizes from Eating Well with Canada’s Food Guide (Health Canada 2007). Current dietary intakes are presented as means, standard deviations, and ranges, and described relative to age- and gender-specific recommendations (National Academy of Sciences 2005, 2010; Health Canada 2007) and data from the Canadian Community Health Survey (CCHS): Cycle 2.2 2004 (Health Canada 2009). Milk and alternatives, fibre, and calcium intakes are presented separately for women aged ≤50 and >50 years to reflect differences in the current dietary recommendations for these age groups. Distributions of nutrient intakes across the sample are provided, including the proportion of women whose intakes fell below, within, and above current guidelines.
Results Study sample A total of 28 women were recruited over a 14-month period. Demographic, clinical, and treatment characteristics are summarized in Table 1. Published by NRC Research Press
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Table 1. Demographic, clinical, and treatment characteristics of the participants. Characteristic (n = 28)
Mean (SD)
Range
Age (y) Ethnicity White Black, Asian, West Asian Marital status Married Single Divorced Education completed High school College University Employment status Employed Leave of absence Unemployed/retired Clinical Stage I II IIIA Menopause status (at diagnosis) Premenopausal Postmenopausal Surgery type Lumpectomy Mastectomy Chemotherapy Number of cycles Duration of treatment (wk) Time from treatment (mo)* Radiation therapy Yes No Planned Hormone therapy Tamoxifen AromataseInhibitor None
49.8±8.5
33–69
n (%)
25 (89%) 3 (11%) 18 (64%) 4 (14%) 6 (22%) 6 (21%) 7 (25%) 15 (54%) 10 (36%) 7 (25%) 11 (39%) 3 (11%) 15 (53%) 10 (36%) 19 (68%) 9 (32%) 15 (54%) 13 (46%) 5.9 (1.9) 15 (4.0) 6.4 (4.4)
2–8 4–24 0.5–13 16 (57%) 5 (18%) 7 (25%)
17 (61%) 5 (18%) 6 (21%)
*Completed.
Dietary changes after diagnosis Twenty-four women (86%) reported that they had made changes to their diet since diagnosis, the majority of which were categorized as positive. The most common change was an increase in vegetables and fruit (75%), followed by a decrease in overall meat consumption or a change to lower fat options (decreased red meat, increased chicken, 57.1%), increased intake of fish (46.4%), and reduced alcohol intake (39.3%). Reports of negative dietary changes were minimal in this sample, with the most common among them being an increase in desserts (14.3%). Many women reported that they had initiated these changes while they were in active treatment (n = 10, 36%), while others (n = 14, 50%) waited until the post-treatment period. Among the latter group, most women reported that trying to make changes in their diet earlier in the treatment trajectory was a challenge because of the stress of their cancer diagnosis and the side effects of treatment. Supplement changes were reported by 61% of women. The most common change was the addition of calcium and (or) vitamin D (32%) and removal of multi-vitamins or single antioxidant nutrients (18%). Dietary changes after diagnosis are summarized in Table 2. Current dietary intake Current dietary intake based on the mean daily values from 3-day food records is summarized in Table 3, relative to national
data from the CCHS and age- and gender-specific recommended intakes. The mean energy intake for the sample was 1883 ± 359 kcal/day. Mean intakes for protein, carbohydrates, and total fat (17.9%, 52.2%, and 28.5%, respectively) fell within the acceptable macronutrient distribution ranges (AMDR) and saturated fat intake (8.9% ± 2.8%) was, on average, below the current guideline (50 years (28.4 ± 8.9 g). Vegetable and fruit servings/day (6.0 ± 3.1) were below the minimum recommendation. The mean intakes of milk and alternatives (servings/day) for women aged ≤50 years (1.4 ± 0.9) and >50 years (1.9 ± 0.8) were below recommendations for both age groups. Mean calcium (≤50 years = 813 ± 299 mg; >50 years = 1032 ± 294) and vitamin D (4.7 ± 3.0 g) intakes from foods alone were also below current recommendations. When supplement use was considered in the calculation of total intake, mean calcium and vitamin D intakes from food and supplements were above the current recommendation for both age groups. Statistical comparisons are not possible; however, compared with women of similar age from the general population, women in this sample appeared, on average, to have lower total fat (28.5% vs. 31.7%) and saturated fat intake (8.9% vs. 10.2%), and higher energy intake (1883% vs. 1767 kcal), fibre intake (26.7 vs. 16.2 g), and vegetable and fruit servings (6.0 vs. 5.1) per day. Among women aged >50 years, the mean milk and alternative (1.9 servings/day) and calcium (1032 mg/day) intakes seemed to be higher than those reported by women of similar age in the CCHS (1.3 servings/day and 740 mg/day, respectively). While mean intakes provide useful comparisons, the distribution of intakes across the sample group is more meaningful. Table 4 shows the percentage of women whose intakes of macronutrients (protein, carbohydrate, total fat) fell below, within, and above the AMDR ranges, below or above the guideline for saturated fat, and below or above the minimum number of servings for vegetables/fruit and milk/alternatives. Calcium and vitamin D intakes represent the proportion of women whose intakes, with and without supplements, fell below or above the estimated average requirement (EAR). Protein intake was within the AMDR for all women and most women (79%) were within the acceptable range for carbohydrates. Similarly, most women were within the recommendation for total fat (79%), with 10% of women below and 11% above the AMDR. Total fat accounted for ≥30% of energy intake (upper AMDR) in 36% of women and 39% were above the guideline for saturated fat. Many women (61%) did not meet the minimum recommendation for total vegetables and fruit, with 36% and 79%, respectively, not meeting the current recommendation to include at least 1 dark green and 1 orange vegetable each day. Thirty-nine percent of women reported 50 years reported less than the recommended number of servings for their age group (3/day). Less than 1 serving per day was reported among 35% and 27% of women aged ≤50 years and >50 years, respectively. These findings are reflected in relatively low intakes of calcium and vitamin D. Based on the EAR cut-point method (Health Canada 2006), the prevalence of inadequate calcium intake from foods alone was high in this sample, with 47% of women aged ≤50 years and 55% of women aged >50 years below the EAR for their age group (800 and 1000 mg, respectively). When combined intake from food and supplements was considered, the prevalence of inadequate intake drops to 18% among women in both age categories. Similarly, vitamin D intake from foods alone was low across the sample group, with 96% of women below the EAR cut-point for adult women (10 g). The prevalence of inadequate intake based on combined intake from food and supplements was 36%. Published by NRC Research Press
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Table 2. Self-reported changes in diet after a diagnosis of breast cancer (n = 28).
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Change
Reported any dietary change Vegetables and fruit Legumes Meat Fish Dairy Breads/cereals Desserts Alcohol Supplements
Type of change
Yes, n (%)
No, n (%)
Positive, n (%)
Negative, n (%)
24 (85.7) 21 (75.0) 7 (25.0) 17 (60.7) 13 (46.4) 8 (28.6) 10 (35.7) 13 (46.4) 11 (39.3) 17 (60.7)
4 (14.3) 7 (25.0) 21 (75.0) 11 (39.3) 15 (53.6) 20 (71.4) 18 (64.3) 15 (53.6) 17 (60.7) 11 (39.3)
21 (75.0) 7 (25.0) 16 (57.1) 13 (46.4) 7 (25) 9 (32.1) 9 (32.1) 11 (39.3)
0 (0) 0 (0) 1 (3.6) 0 (0) 1 (3.6) 1 (3.6) 4 (14.3) 0 (0)
Table 3. Current dietary intake relative to the Canadian Community Health Survey (CCHS) (2004; Health Canada 2009) and age-/gender-specific recommendations (n = 28). Recommended intakes†
Dietary intake*
Mean (SD)
Range
CCHS mean
Energy (kcal) Protein (g) % Energy Carbohydrate (g) % Energy Total fat (g) % Energy Saturated fat (% energy) Fibre (g) All women ≤50 y >50 y Vegetables (servings/d) Dark green Orange Fruit (servings/d) Vegetables and fruit (servings/d) Milk/alternatives (servings/d) All women ≤50 y >50 y Calcium (mg) Foods All women ≤50 y >50 y Foods + supplements All women ≤50 y >50 y Vitamin D (g / IU) Foods Foods + supplements
1883 (359) 85.9 (18.7) 17.9 (3.4) 251.6 (64.4) 52.2 (7.7) 61.3 (16.2) 28.5 (5.6) 8.9 (2.8)
933–2553 30.6–137.8 12.1–28.3 148.1–422.9 36.7–68.8 19.4–91.6 18.4–40.8 3.7–13.6
1767 73.8 16.8 217.4 49.1 65.2 31.7 10.2
26.7 (10.9) 25.6 (12.3) 28.4 (8.9) 3.3 (2.3) 1.1 (0.87) 0.6 (0.6) 2.7 (1.5) 6.0 (3.1)
7.4–46.6 7.4–46.6 13.6–42.1 0.2–9.5 0.0–3.2 0.0–2.2 0.8–6.6 1.2–15.0
16.2 15.7 16.6
25 21
5.1
7–8
1.6 (0.9) 1.4 (0.9) 1.9 (0.8)
0.0–2.9 0.0–2.8 0.7–2.9
1.4 1.5 1.3
2 3
899 (311) 813 (299) 1032 (294)
264–1577 264–1577 520–1437
780 827 740
1000 1200
1350 (537) 1224 (477) 1614 (587)
(496–2270) (496–2144) (878–2270)
4.7 (3) / 188 (121) 19 (16) / 745 (620)
1–12 / 40–492 1–62 / 40–2492
1677–2674‡ 10–35 45–65 20–35 50 years did not meet the recommended number of milk and alternative servings for their age group. The prevalence of inadequate calcium and vitamin D intakes from food alone was high across the sample, but were substantially lower when total calcium and vitamin D intakes from food and supplements were considered. This finding highlights the need for dietary counseling around food and supplemental sources of these nutrients in this population. Treatment-induced menopause could not be evaluated in this cohort (length of time from treatment 50 years (1200 mg) within the first few months of treatment. It is important to keep in mind that vitamin D status is influenced by sun exposure as well, although less so in the Canadian climate during the winter months (Health Canada 2007). Adequate dietary and supplemental sources are especially important when reduced year-round sunlight limits the endogenous conversion of 7-dehydrocholesterol to previtamin D3. Of particular interest was the finding that many women reported having initiated positive changes in diet during active treatment. There is some evidence to suggest that a diagnosis of breast cancer may represent a “teachable moment”, in which women are highly motivated to make lifestyle changes that will promote long-term disease-free survival and overall wellness (Demark-Wahnefried et al. 2000; McBride et al. 2000). It has been suggested in the literature, and supported by the current study, that some women may need time to recover from the turmoil of a cancer diagnosis and its treatment before they are ready for di-
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etary change (Thomson et al. 2002). Our results demonstrate, however, that some women may be willing and able to implement positive changes earlier in the treatment trajectory. These women reported some challenges (e.g., fatigue, stress, nausea) in making these changes during treatment; however, they appeared to have supports in place (e.g., cooking assistance, social support) to motivate and reinforce their efforts. This has important implications for dietary counseling, suggesting that early intervention may be effective in promoting dietary habits that will assist with weight management and overall health. It is clear, however, that dietary guidance must be presented within the context of potential barriers to healthy eating, and delivered with a sensitivity to the challenges that women face as they are undergoing treatment. This study has some limitations. First, the survey used to evaluate self-reported changes in diet is not a validated research instrument. It is noteworthy, however, that data on dietary changes appear to be consistent with current dietary intake, with a high proportion of women reporting an increase in vegetables and fruit, for example, which is reflected in relatively high intakes of vegetable and fruit servings compared with national survey data. Moreover, earlier studies have reported good concordance between self-reported changes in diet and dietary changes captured by FFQ before and after diagnosis (Wayne et al. 2004) and current dietary intake assessed by repeated 24-h recalls (Thomson et al. 2002). This survey has been used previously with breast cancer survivors (Maunsell et al. 2002), thus affording the opportunity to provide direct comparisons. We did not quantify dietary change in this study; however, self-reported changes were evaluated in the context of current dietary intake estimated from 3-day food records, which is an important link in understanding how these changes impact on the overall quality of the diet. In addition, we did not have baseline dietary data, which may have influenced the perception of dietary change data. For example, 39% of women reported a reduction in alcohol intake; however, many others reported that they had consumed little or no alcohol before diagnosis and reported no change in alcohol consumption since their diagnosis. Once again, a precise measure of current dietary intake provided context for dietary change data. It is possible that self-reported dietary change and dietary intake were subject to the well-documented limitations of social expectation bias and under-reporting (Hill and Davies 2001; Caan et al. 2000). Energy intake in this sample, however, was higher than previous reports in breast cancer survivors and women of similar age from the general population, suggesting that social desirability and under-reporting may be less pronounced in this study. Two weekdays and 1 weekend day were included in each 3-day record, to control for possible day-of-the-week effects, but it is possible that seasonal variation in eating patterns may have influenced dietary intake. Data collection took place over a 14-month period, with diet records equally dispersed across the summer and winter seasons, which suggests that seasonal variation likely did not have a significant impact on the data. Finally, dietary data in the current study may be associated with a self-selection bias, reflecting systematic differences in the type of women who might choose to participate in a study of this nature, and may not be representative of the population of breast cancer survivors. The age distribution of women in this sample appears to be a little younger that the distribution of Canadian women who are diagnosed with breast cancer (Canadian Cancer Society’s Steering Committee on Cancer Statistics 2012). This may have had an impact on generalizability of our results, since there is some evidence to suggest that younger women are more likely to make dietary changes after a diagnosis of breast cancer (Thomson et al. 2002; Wayne et al. 2004). Although many of the women who volunteered for this study appeared to have a strong interest in healthy eating and exercise, this is consistent with other studies in which breast cancer survivors are described as Published by NRC Research Press
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highly motivated to make positive changes in lifestyle. The study sample was part of a larger study, in which women were participating in qualitative interviews. In keeping with the in-depth nature of qualitative analysis, the sample size was relatively small. Comparisons of dietary changes and current dietary intake, by age and clinical stage in a larger sample of women, are important considerations for future study. In summary, the majority of women in this sample of early stage breast cancer survivors reported positive changes in diet since their diagnosis. Dietary changes were largely consistent with current recommendations for cancer prevention; however, some women were still above the recommendations for total and saturated fat and many were below the minimum recommendation for vegetables and fruit, and milk and alternatives. The prevalence of inadequate calcium and vitamin D intakes from food alone was high in the sample. Our findings add to a limited number of studies in which dietary changes among breast cancer survivors have been reported in the context of current dietary intake. Improving our understanding of dietary habits after diagnosis, including dietary changes that women are making on their own, when these changes are initiated and how dietary intakes compare to current recommendations, will inform appropriate targets and timing for nutrition counseling that will help to guide dietetic practice and nutrition intervention in this population.
Acknowledgements The authors wish to acknowledge the Canadian Foundation for Dietetic Research for their support of this research. Vivienne Vance was funded by a Doctoral Research Award from the Canadian Institutes of Health Research.
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Psychological impact of diagnosis and risk reduction among cancer survivors. Psychooncology, 9: 418–427. doi:10.1002/1099-1611(200009/10)9:53.3.CO;2-5. PMID:11038480. National Academy of Sciences. 2005. Dietary reference intakes for energy, carbohydrates, fiber, fat, fatty acids, cholesterol, protein, and amino acids (macronutrients). Institute of Medicine. National Academies Press, Washington, DC, USA. National Academy of Sciences. 2010. Dietary reference intakes for calcium and vitamin D. Institute of Medicine, Report brief. Available from http:// www.iom.edu/⬃/media/Files/Report%20Files/2010/Dietary-ReferenceIntakes-for-Calcium-and-Vitamin-Vitamin%20D%20and%20Calcium%20 2010%20Report%20Brief.pdf. [Accessed 6 May 2012.] National Cancer Institute. 2011a. Surveillance, Epidemiology and End Results (SEER) Program. Available from http://seer.cancer.gov/statfacts/html/breast. html. [Accessed 22 July 2011.] National Cancer Institute. 2011b. NCI Dictionary of Cancer Terms. Available from http://www.cancer.gov/dictionary?cdrid=450125 [accessed 28 April 2011]. National Institutes of Health. 2011. Calcium and vitamin D: Important at every age. Available from http://www.niams.nih.gov/Health_info/bone/ Bone_Health/Nutrition/default.asp. [Accessed 2 May 2012.] Nichols, H.B., Trentham-Dietz, A., Egan, K.M., Titus-Ernstoff, L., Holmes, M.D., Bersch, A.J., et al. 2009. Body mass index before and after breast cancer diagnosis: Associations with all-cause, breast cancer and cardiovascular disease mortality. Cancer Epidemiol. Biomarkers Prev. 18(5): 1403–1409. doi:10. 1158/1055-9965.EPI-08-1094. PMID:19366908. Pierce, J.P., Natarajan, L., Caan, B.J., Parker, B.A., Greenberg, E.R., Flatt, S.W., et al. 2007. Influence of a diet very high in vegetables, fruit, and fiber and low in fat on prognosis following treatment for breast cancer. JAMA, 298(3): 289–298. doi:10.1001/jama.298.3.289. PMID:17635889. Robinson, L.E., and Graham, T.E. 2004. Metabolic syndrome, a cardiovascular disease risk factor: Role of adipocytokines and impact of diet and physical activity. Can. J. Appl. Physiol. 29(6): 808–829. doi:10.1139/h04-053. PMID: 15630152. Rock, C.L., and Demark-Wahnefried, W. 2002. Nutrition and survival after the diagnosis of breast cancer: a review of the evidence. J. Clin. Oncol. 20(15): 3302–3316. doi:10.1200/JCO.2002.03.008. PMID:12149305. Rock, C.L., Natarajan, L., Pu, M., Thomson, C.A., Flatt, S.W., Caan, B.J., et al. 2009. Longitudinal biological exposure to carotenoids is associated with breast cancer-free survival in the Women’s Healthy Eating and Living Study. Cancer Published by NRC Research Press
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Epidemiol. Biomarkers Prev. 18(2): 486–494. doi:10.1158/1055-9965.EPI-080809. PMID:19190138. Thivat, E., Therondel, S., Lapirot, O., Abrial, C., Gimbergues, P., Gadea, E., et al. 2010. Weight change during chemotherapy changes the prognosis in non metastatic breast cancer for the worst. BMC Cancer, 10: 648. doi:10.1186/14712407-10-648. PMID:21108799. Thomson, C.A., Flatt, S.W., Rock, C.L., Ritenbaugh, C., Newman, V., and Pierce, J.P. 2002. Increased fruit, vegetable and fiber intake and lower fat intake reported among women previously treated for invasive breast cancer. J. Am. Diet. Assoc. 102: 801–808. doi:10.1016/S0002-8223(02)90180-X. PMID: 12067045. Trabulsi, J., and Schoeller, D.A. 2001. Evaluation of dietary assessment instruments against doubly labeled water, a biomarker of habitual intake. Am. J. Physiol. Endocrinol. Metab. 281: E891–E899. PMID:11595643. Vance, V., Mourtzakis, M., McCargar, L., and Hanning, R. 2011. Weight gain in
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breast cancer survivors: prevalence, pattern and health consequences. Obes. Rev. 12: 282–294. doi:10.1111/j.1467-789X.2010.00805.x. PMID:20880127. Visovsky, C. 2006. Muscle strength, body composition, and physical activity in women receiving chemotherapy for breast cancer. Integr. Cancer Ther. 5(3): 183–191. doi:10.1177/1534735406291962. PMID:16880422. Wayne, S.J., Lopez, S., Butler, L.M., Baumgartner, K., Baumgartner, R.N., and Ballard-Barbash, R. 2004. Changes in dietary intake after diagnosis of breast cancer. J. Am. Diet. Assoc. 104: 1561–1568. doi:10.1016/j.jada.2004.07.028. PMID:15389414. Wingo, P.A., Gloeckler Ries, L.A., Parker, S.L., and Heath, C.W. 1998. Long-term cancer patient survival in the United States. Cancer Epidemiol. Biomarkers Prev. 7: 271–282. PMID:9568781. World Cancer Research Fund/American Institute for Cancer Research. 2007. Food, Nutrition, Physical Activity, and the Prevention of Cancer: a Global Perspective. AICR, Washington, DC, USA.
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ARTICLE Dietary changes and food intake in the first year after breast cancer treatment1 Appl. Physiol. Nutr. Metab. Downloaded from www.nrcresearchpress.com by CONCORDIA UNIV on 05/30/14 For personal use only.
Vivienne Vance, Sharon Campbell, Linda McCargar, Marina Mourtzakis, and Rhona Hanning
Abstract: Understanding dietary habits of women after breast cancer is a critical first step in developing nutrition guidelines that will support weight management and optimal health in survivorship; however, limited data are available. The objective of this study was to describe changes in diet among breast cancer survivors in the first year after treatment, and to evaluate these changes in the context of current dietary intake. Changes in diet were assessed in 28 early stage breast cancer survivors, using a self-reported survey in which women identified changes in food intake since their diagnosis. Current dietary intake was estimated from 3-day food records and described relative to current recommendations. The majority of women reported changes in diet after diagnosis, most common being an increase in vegetables/fruit and fish, lower intake of red meat, and reduced alcohol. Many women reported that these changes were initiated during active treatment. Dietary changes were largely consistent with current recommendations for cancer prevention; however, some women were still above the guidelines for total and saturated fat, and many were below recommendations for vegetables/fruit, milk/alternatives, calcium, and vitamin D. Evidence that some women are willing and able to initiate positive changes in diet early in the treatment trajectory suggests that early intervention may be effective in promoting dietary habits that will assist with weight management and overall health. Data on current dietary intake highlights several possible targets for dietary intervention in this population. Key words: diet, dietary change, breast cancer, body weight, survivorship. Résumé : Comprendre les habitudes alimentaires des femmes ayant eu un cancer du sein est la première étape critique pour élaborer des directives en matière de nutrition qui aideront au contrôle du poids et au maintien d’une santé optimale chez les survivantes; toutefois, il y a peu d’études sur ce sujet. Cette étude se propose de décrire les modifications du régime alimentaire chez les survivantes du cancer du sein durant la première année suivant le traitement et d’évaluer ces modifications dans le contexte du régime alimentaire actuel. On évalue les modifications au régime alimentaire depuis le diagnostic de 28 survivantes du cancer du sein au stade précoce au moyen d’une enquête d’autoévaluation demandant d’indiquer les changements effectués a` l’apport alimentaire. On évalue l’apport alimentaire d’après le rappel de 3 jours et on le compare aux recommandations actuelles. La majorité des femmes rapportent des modifications dans leur régime alimentaire a` la suite du diagnostic, les plus fréquentes étant plus de fruits/légumes et de poisson, moins de viande rouge et d’alcool. Plusieurs femmes rapportent que ces modifications ont été amorcées durant le traitement. Ces modifications des habitudes alimentaires étaient très conformes aux recommandations actuelles pour la prévention du cancer, mais quelques femmes consommaient plus de gras, total et saturé, et moins de fruits/légumes, lait–substituts, calcium et vitamine D que ne le stipulent les recommandations. Le fait que des femmes veulent et arrivent a` modifier positivement leur régime alimentaire au début de la trajectoire du traitement suggère qu’une intervention précoce semble efficace pour la promotion de bonnes habitudes alimentaires utiles au contrôle du poids et a` la santé globale. Les données au sujet de l’apport alimentaire actuel mettent en évidence plusieurs cibles a` viser pour des interventions en matière d’alimentation auprès de cette population. [Traduit par la Rédaction] Mots-clés : régime alimentaire, modification alimentaire, cancer du sein, poids corporel, survie.
Introduction The population of breast cancer survivors in Canada and the United States is growing substantially, with more than 250 000 new cases expected each year and significant improvements in survival rates since the mid-1980s (Canadian Cancer Society’s Steering Committee on Cancer Statistics 2011; National Cancer Institute 2011a). Many of these women gain weight, both during and after treatment (Vance et al. 2011). Furthermore, with or without weight gain, gains in body fat and loss of lean tissue are prevalent in
this population (Vance et al. 2011; Rock and Demark-Wahnefried 2002; Visovsky 2006). These unfavourable changes in body composition are distressing for many women (Knobf 1986; Halbert et al. 2008) and may lead to metabolic disturbance (Robinson and Graham 2004), increased risk of obesity-related disorders (Brown et al. 1993; Wingo et al. 1998), and poorer prognosis (Nichols et al. 2009; Chen et al. 2010; Thivat et al. 2010). As prevalence increases, the need for dietary counseling and nutrition intervention to support healthy eating, weight management, and optimal health after diagnosis is expected to grow.
Received 26 August 2013. Accepted 6 November 2013. V. Vance,* S. Campbell, and R. Hanning. School of Public Health and Health Systems, University of Waterloo, Waterloo, ON N2L 3G1, Canada. L. McCargar. Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB T6G 2E1, Canada. M. Mourtzakis.† Department of Kinesiology, University of Waterloo, Waterloo, ON N2L 3G1, Canada. Corresponding author: Vivienne Vance (e-mail: [email protected]). *Present address: Health Sciences Program, Wilfrid Laurier University, 75 University Ave, Waterloo, ON N2L 3C5, Canada. †All editorial decisions for this paper were made by David Ma and Terry Graham. 1This paper is a part of a Special Issue entitled The role of diet, body composition, and physical activity on cancer prevention, treatment, and survivorship. Appl. Physiol. Nutr. Metab. 39: 707–714 (2014) dx.doi.org/10.1139/apnm-2013-0400
Published at www.nrcresearchpress.com/apnm on 20 November 2013.
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The ideal diet for breast cancer survivors is uncertain at this time; however, current evidence suggests that a diet aimed at primary prevention may also improve long-term disease-free status (World Cancer Research Fund/American Institute for Cancer Research 2007) and overall survival (Kroenke et al. 2005; Kwan et al. 2009). Thus, a predominantly plant-based diet that promotes a healthy body weight, is low in fat, rich in whole grains, and comprises a variety of fruits and vegetables is currently recommended for women who have undergone treatment for breast cancer (Hauner et al. 2011; BC Cancer Agency 2012). In addition, adequate calcium and vitamin D intake is necessary to support bone health, particularly since many breast cancer survivors are menopausal at diagnosis (Canadian Cancer Society’s Steering Committee on Cancer Statistics 2012) and many others will become menopausal as a result of treatment (Canadian Breast Cancer Foundation 2012a). With these guidelines in mind, understanding dietary habits of women after diagnosis is an important first step in developing intervention strategies. At this time there are very limited data concerning dietary changes made by women after a breast cancer diagnosis, particularly early in the treatment trajectory when these changes are initiated, and how nutrient intakes in this population compare with current recommendations. The objective of this study was to describe selfreported changes in diet among breast cancer survivors (National Cancer Institute 2011b), who were within the first year of completing chemotherapy treatment, and to evaluate these changes in the context of current dietary intake. These findings may help to identify factors associated with energy imbalance after primary treatment and will provide a preliminary basis on which to develop nutrition guidelines to inform dietetic counseling and intervention.
Materials and methods Participant recruitment Data for this study were collected as part of a more extensive study in which breast cancer survivors participated in qualitative interviews to explore individual experiences of food intake and weight change during chemotherapy. Participants were recruited from southwestern Ontario, Canada. Eligibility requirements included female breast cancer survivors aged >18 years, clinical stage I–IIIA, within 12 months of completing chemotherapy, and able to communicate freely in English (oral and written). The study received clearance from the Office of Research Ethics, University of Waterloo. Participants were recruited through professional organizations/events (e.g., Canadian Breast Cancer Foundation Run for the Cure), community support groups, and local businesses. Advertisements were also posted in several newspapers, the Well-Fit Centre at the University of Waterloo (group exercise program for cancer patients), and the Grand River Regional Cancer Centre, Kitchener, Ontario. Interested participants contacted the researcher via telephone or email, were screened for eligibility, and provided with a detailed information letter. Eligible participants were contacted again within 1 week to review study details and respond to questions. Interviews were scheduled within 2 weeks in the participant’s home or at the University of Waterloo, based on participant preference. Demographic, clinical and treatment information were collected via detailed questionnaire, which was completed with the researcher. Written consent was provided by all participants. Dietary changes after diagnosis Changes in diet after diagnosis were assessed using an initial “filter” question that asked “since your diagnosis have you made any changes to the kinds of foods you eat?” Women who indicated that they had made changes to their diet were asked to elaborate about specific changes in food groups/dietary components. Nine
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diet categories, adapted from previous research with breast cancer survivors (Maunsell et al. 2002) and grounded in current dietary recommendations for healthy eating (Health Canada 2007), were evaluated including vegetables and fruit, legumes, meat, fish, dairy products, breads/cereals, desserts, alcohol, and supplements. Participants were asked to indicate whether they had “introduced”, “increased”, “decreased”, or “eliminated” these items from their diet since their diagnosis. In addition, 4 items were further explored to determine if there had been a “change in type”, including meat, dairy products, breads/cereals, and supplements. Based on the work of Maunsell et al. (2002), changes were categorized as positive if intake of vegetables and fruit, legumes, and fish were reported as increased (or introduced) and if intake of meat, desserts, and alcohol were reported as decreased (or eliminated). Changes in dairy products and breads/cereals were considered positive if women reported consuming products with a lower fat content or higher fibre content, respectively. Added to this study was 1 additional positive change: a “change in type” for meat intake (lower fat content). Changes in dietary supplement use were of interest; however, in the absence of clear evidence (Greenlee et al. 2009) these changes were not classified as positive or negative. Three-day food records Current dietary intake was assessed using a 3-day food record. Two weekdays and 1 weekend day were included, to control for possible day-of-the-week effects (Trabulsi and Schoeller 2001). Detailed verbal and written instructions for recording daily food intake and a “sample day” were provided. Participants were encouraged to provide as much detail as possible and to use household measures (teaspoons, measuring cups, scales) and food labels to estimate serving sizes. During the recording period, participants were contacted by telephone or email to see if they had any questions or concerns. Completed records were reviewed with participants for clarification and completeness. Data analysis Descriptive statistics were used to characterize the sample group and to identify the nature and extent of self-reported changes in diet since diagnosis. Specific components of current dietary intake were selected for analysis (energy, macronutrients, fibre, vegetables/fruits, milk/alternatives, calcium, vitamin D), based on current guidelines to support weight management and optimal health after diagnosis. Nutrient analysis was conducted using The Food Processor SQL version 10.5.2 (Esha Research, Salem, Ore., USA), including the current Canadian Nutrient File Database (Health Canada 2010). Servings of vegetables/fruit (total, dark green/orange vegetables) and milk/alternatives were hand calculated, based on servings sizes from Eating Well with Canada’s Food Guide (Health Canada 2007). Current dietary intakes are presented as means, standard deviations, and ranges, and described relative to age- and gender-specific recommendations (National Academy of Sciences 2005, 2010; Health Canada 2007) and data from the Canadian Community Health Survey (CCHS): Cycle 2.2 2004 (Health Canada 2009). Milk and alternatives, fibre, and calcium intakes are presented separately for women aged ≤50 and >50 years to reflect differences in the current dietary recommendations for these age groups. Distributions of nutrient intakes across the sample are provided, including the proportion of women whose intakes fell below, within, and above current guidelines.
Results Study sample A total of 28 women were recruited over a 14-month period. Demographic, clinical, and treatment characteristics are summarized in Table 1. Published by NRC Research Press
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Table 1. Demographic, clinical, and treatment characteristics of the participants. Characteristic (n = 28)
Mean (SD)
Range
Age (y) Ethnicity White Black, Asian, West Asian Marital status Married Single Divorced Education completed High school College University Employment status Employed Leave of absence Unemployed/retired Clinical Stage I II IIIA Menopause status (at diagnosis) Premenopausal Postmenopausal Surgery type Lumpectomy Mastectomy Chemotherapy Number of cycles Duration of treatment (wk) Time from treatment (mo)* Radiation therapy Yes No Planned Hormone therapy Tamoxifen AromataseInhibitor None
49.8±8.5
33–69
n (%)
25 (89%) 3 (11%) 18 (64%) 4 (14%) 6 (22%) 6 (21%) 7 (25%) 15 (54%) 10 (36%) 7 (25%) 11 (39%) 3 (11%) 15 (53%) 10 (36%) 19 (68%) 9 (32%) 15 (54%) 13 (46%) 5.9 (1.9) 15 (4.0) 6.4 (4.4)
2–8 4–24 0.5–13 16 (57%) 5 (18%) 7 (25%)
17 (61%) 5 (18%) 6 (21%)
*Completed.
Dietary changes after diagnosis Twenty-four women (86%) reported that they had made changes to their diet since diagnosis, the majority of which were categorized as positive. The most common change was an increase in vegetables and fruit (75%), followed by a decrease in overall meat consumption or a change to lower fat options (decreased red meat, increased chicken, 57.1%), increased intake of fish (46.4%), and reduced alcohol intake (39.3%). Reports of negative dietary changes were minimal in this sample, with the most common among them being an increase in desserts (14.3%). Many women reported that they had initiated these changes while they were in active treatment (n = 10, 36%), while others (n = 14, 50%) waited until the post-treatment period. Among the latter group, most women reported that trying to make changes in their diet earlier in the treatment trajectory was a challenge because of the stress of their cancer diagnosis and the side effects of treatment. Supplement changes were reported by 61% of women. The most common change was the addition of calcium and (or) vitamin D (32%) and removal of multi-vitamins or single antioxidant nutrients (18%). Dietary changes after diagnosis are summarized in Table 2. Current dietary intake Current dietary intake based on the mean daily values from 3-day food records is summarized in Table 3, relative to national
data from the CCHS and age- and gender-specific recommended intakes. The mean energy intake for the sample was 1883 ± 359 kcal/day. Mean intakes for protein, carbohydrates, and total fat (17.9%, 52.2%, and 28.5%, respectively) fell within the acceptable macronutrient distribution ranges (AMDR) and saturated fat intake (8.9% ± 2.8%) was, on average, below the current guideline (50 years (28.4 ± 8.9 g). Vegetable and fruit servings/day (6.0 ± 3.1) were below the minimum recommendation. The mean intakes of milk and alternatives (servings/day) for women aged ≤50 years (1.4 ± 0.9) and >50 years (1.9 ± 0.8) were below recommendations for both age groups. Mean calcium (≤50 years = 813 ± 299 mg; >50 years = 1032 ± 294) and vitamin D (4.7 ± 3.0 g) intakes from foods alone were also below current recommendations. When supplement use was considered in the calculation of total intake, mean calcium and vitamin D intakes from food and supplements were above the current recommendation for both age groups. Statistical comparisons are not possible; however, compared with women of similar age from the general population, women in this sample appeared, on average, to have lower total fat (28.5% vs. 31.7%) and saturated fat intake (8.9% vs. 10.2%), and higher energy intake (1883% vs. 1767 kcal), fibre intake (26.7 vs. 16.2 g), and vegetable and fruit servings (6.0 vs. 5.1) per day. Among women aged >50 years, the mean milk and alternative (1.9 servings/day) and calcium (1032 mg/day) intakes seemed to be higher than those reported by women of similar age in the CCHS (1.3 servings/day and 740 mg/day, respectively). While mean intakes provide useful comparisons, the distribution of intakes across the sample group is more meaningful. Table 4 shows the percentage of women whose intakes of macronutrients (protein, carbohydrate, total fat) fell below, within, and above the AMDR ranges, below or above the guideline for saturated fat, and below or above the minimum number of servings for vegetables/fruit and milk/alternatives. Calcium and vitamin D intakes represent the proportion of women whose intakes, with and without supplements, fell below or above the estimated average requirement (EAR). Protein intake was within the AMDR for all women and most women (79%) were within the acceptable range for carbohydrates. Similarly, most women were within the recommendation for total fat (79%), with 10% of women below and 11% above the AMDR. Total fat accounted for ≥30% of energy intake (upper AMDR) in 36% of women and 39% were above the guideline for saturated fat. Many women (61%) did not meet the minimum recommendation for total vegetables and fruit, with 36% and 79%, respectively, not meeting the current recommendation to include at least 1 dark green and 1 orange vegetable each day. Thirty-nine percent of women reported 50 years reported less than the recommended number of servings for their age group (3/day). Less than 1 serving per day was reported among 35% and 27% of women aged ≤50 years and >50 years, respectively. These findings are reflected in relatively low intakes of calcium and vitamin D. Based on the EAR cut-point method (Health Canada 2006), the prevalence of inadequate calcium intake from foods alone was high in this sample, with 47% of women aged ≤50 years and 55% of women aged >50 years below the EAR for their age group (800 and 1000 mg, respectively). When combined intake from food and supplements was considered, the prevalence of inadequate intake drops to 18% among women in both age categories. Similarly, vitamin D intake from foods alone was low across the sample group, with 96% of women below the EAR cut-point for adult women (10 g). The prevalence of inadequate intake based on combined intake from food and supplements was 36%. Published by NRC Research Press
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Table 2. Self-reported changes in diet after a diagnosis of breast cancer (n = 28).
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Change
Reported any dietary change Vegetables and fruit Legumes Meat Fish Dairy Breads/cereals Desserts Alcohol Supplements
Type of change
Yes, n (%)
No, n (%)
Positive, n (%)
Negative, n (%)
24 (85.7) 21 (75.0) 7 (25.0) 17 (60.7) 13 (46.4) 8 (28.6) 10 (35.7) 13 (46.4) 11 (39.3) 17 (60.7)
4 (14.3) 7 (25.0) 21 (75.0) 11 (39.3) 15 (53.6) 20 (71.4) 18 (64.3) 15 (53.6) 17 (60.7) 11 (39.3)
21 (75.0) 7 (25.0) 16 (57.1) 13 (46.4) 7 (25) 9 (32.1) 9 (32.1) 11 (39.3)
0 (0) 0 (0) 1 (3.6) 0 (0) 1 (3.6) 1 (3.6) 4 (14.3) 0 (0)
Table 3. Current dietary intake relative to the Canadian Community Health Survey (CCHS) (2004; Health Canada 2009) and age-/gender-specific recommendations (n = 28). Recommended intakes†
Dietary intake*
Mean (SD)
Range
CCHS mean
Energy (kcal) Protein (g) % Energy Carbohydrate (g) % Energy Total fat (g) % Energy Saturated fat (% energy) Fibre (g) All women ≤50 y >50 y Vegetables (servings/d) Dark green Orange Fruit (servings/d) Vegetables and fruit (servings/d) Milk/alternatives (servings/d) All women ≤50 y >50 y Calcium (mg) Foods All women ≤50 y >50 y Foods + supplements All women ≤50 y >50 y Vitamin D (g / IU) Foods Foods + supplements
1883 (359) 85.9 (18.7) 17.9 (3.4) 251.6 (64.4) 52.2 (7.7) 61.3 (16.2) 28.5 (5.6) 8.9 (2.8)
933–2553 30.6–137.8 12.1–28.3 148.1–422.9 36.7–68.8 19.4–91.6 18.4–40.8 3.7–13.6
1767 73.8 16.8 217.4 49.1 65.2 31.7 10.2
26.7 (10.9) 25.6 (12.3) 28.4 (8.9) 3.3 (2.3) 1.1 (0.87) 0.6 (0.6) 2.7 (1.5) 6.0 (3.1)
7.4–46.6 7.4–46.6 13.6–42.1 0.2–9.5 0.0–3.2 0.0–2.2 0.8–6.6 1.2–15.0
16.2 15.7 16.6
25 21
5.1
7–8
1.6 (0.9) 1.4 (0.9) 1.9 (0.8)
0.0–2.9 0.0–2.8 0.7–2.9
1.4 1.5 1.3
2 3
899 (311) 813 (299) 1032 (294)
264–1577 264–1577 520–1437
780 827 740
1000 1200
1350 (537) 1224 (477) 1614 (587)
(496–2270) (496–2144) (878–2270)
4.7 (3) / 188 (121) 19 (16) / 745 (620)
1–12 / 40–492 1–62 / 40–2492
1677–2674‡ 10–35 45–65 20–35 50 years did not meet the recommended number of milk and alternative servings for their age group. The prevalence of inadequate calcium and vitamin D intakes from food alone was high across the sample, but were substantially lower when total calcium and vitamin D intakes from food and supplements were considered. This finding highlights the need for dietary counseling around food and supplemental sources of these nutrients in this population. Treatment-induced menopause could not be evaluated in this cohort (length of time from treatment 50 years (1200 mg) within the first few months of treatment. It is important to keep in mind that vitamin D status is influenced by sun exposure as well, although less so in the Canadian climate during the winter months (Health Canada 2007). Adequate dietary and supplemental sources are especially important when reduced year-round sunlight limits the endogenous conversion of 7-dehydrocholesterol to previtamin D3. Of particular interest was the finding that many women reported having initiated positive changes in diet during active treatment. There is some evidence to suggest that a diagnosis of breast cancer may represent a “teachable moment”, in which women are highly motivated to make lifestyle changes that will promote long-term disease-free survival and overall wellness (Demark-Wahnefried et al. 2000; McBride et al. 2000). It has been suggested in the literature, and supported by the current study, that some women may need time to recover from the turmoil of a cancer diagnosis and its treatment before they are ready for di-
Appl. Physiol. Nutr. Metab. Vol. 39, 2014
etary change (Thomson et al. 2002). Our results demonstrate, however, that some women may be willing and able to implement positive changes earlier in the treatment trajectory. These women reported some challenges (e.g., fatigue, stress, nausea) in making these changes during treatment; however, they appeared to have supports in place (e.g., cooking assistance, social support) to motivate and reinforce their efforts. This has important implications for dietary counseling, suggesting that early intervention may be effective in promoting dietary habits that will assist with weight management and overall health. It is clear, however, that dietary guidance must be presented within the context of potential barriers to healthy eating, and delivered with a sensitivity to the challenges that women face as they are undergoing treatment. This study has some limitations. First, the survey used to evaluate self-reported changes in diet is not a validated research instrument. It is noteworthy, however, that data on dietary changes appear to be consistent with current dietary intake, with a high proportion of women reporting an increase in vegetables and fruit, for example, which is reflected in relatively high intakes of vegetable and fruit servings compared with national survey data. Moreover, earlier studies have reported good concordance between self-reported changes in diet and dietary changes captured by FFQ before and after diagnosis (Wayne et al. 2004) and current dietary intake assessed by repeated 24-h recalls (Thomson et al. 2002). This survey has been used previously with breast cancer survivors (Maunsell et al. 2002), thus affording the opportunity to provide direct comparisons. We did not quantify dietary change in this study; however, self-reported changes were evaluated in the context of current dietary intake estimated from 3-day food records, which is an important link in understanding how these changes impact on the overall quality of the diet. In addition, we did not have baseline dietary data, which may have influenced the perception of dietary change data. For example, 39% of women reported a reduction in alcohol intake; however, many others reported that they had consumed little or no alcohol before diagnosis and reported no change in alcohol consumption since their diagnosis. Once again, a precise measure of current dietary intake provided context for dietary change data. It is possible that self-reported dietary change and dietary intake were subject to the well-documented limitations of social expectation bias and under-reporting (Hill and Davies 2001; Caan et al. 2000). Energy intake in this sample, however, was higher than previous reports in breast cancer survivors and women of similar age from the general population, suggesting that social desirability and under-reporting may be less pronounced in this study. Two weekdays and 1 weekend day were included in each 3-day record, to control for possible day-of-the-week effects, but it is possible that seasonal variation in eating patterns may have influenced dietary intake. Data collection took place over a 14-month period, with diet records equally dispersed across the summer and winter seasons, which suggests that seasonal variation likely did not have a significant impact on the data. Finally, dietary data in the current study may be associated with a self-selection bias, reflecting systematic differences in the type of women who might choose to participate in a study of this nature, and may not be representative of the population of breast cancer survivors. The age distribution of women in this sample appears to be a little younger that the distribution of Canadian women who are diagnosed with breast cancer (Canadian Cancer Society’s Steering Committee on Cancer Statistics 2012). This may have had an impact on generalizability of our results, since there is some evidence to suggest that younger women are more likely to make dietary changes after a diagnosis of breast cancer (Thomson et al. 2002; Wayne et al. 2004). Although many of the women who volunteered for this study appeared to have a strong interest in healthy eating and exercise, this is consistent with other studies in which breast cancer survivors are described as Published by NRC Research Press
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Vance et al.
highly motivated to make positive changes in lifestyle. The study sample was part of a larger study, in which women were participating in qualitative interviews. In keeping with the in-depth nature of qualitative analysis, the sample size was relatively small. Comparisons of dietary changes and current dietary intake, by age and clinical stage in a larger sample of women, are important considerations for future study. In summary, the majority of women in this sample of early stage breast cancer survivors reported positive changes in diet since their diagnosis. Dietary changes were largely consistent with current recommendations for cancer prevention; however, some women were still above the recommendations for total and saturated fat and many were below the minimum recommendation for vegetables and fruit, and milk and alternatives. The prevalence of inadequate calcium and vitamin D intakes from food alone was high in the sample. Our findings add to a limited number of studies in which dietary changes among breast cancer survivors have been reported in the context of current dietary intake. Improving our understanding of dietary habits after diagnosis, including dietary changes that women are making on their own, when these changes are initiated and how dietary intakes compare to current recommendations, will inform appropriate targets and timing for nutrition counseling that will help to guide dietetic practice and nutrition intervention in this population.
Acknowledgements The authors wish to acknowledge the Canadian Foundation for Dietetic Research for their support of this research. Vivienne Vance was funded by a Doctoral Research Award from the Canadian Institutes of Health Research.
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